Topics
Number System(Consolidating the Sense of Numberness)
Number System
Estimation
Ratio and Proportion
Algebra
Numbers in India and International System (With Comparison)
Geometry
Place Value
Mensuration
Natural Numbers and Whole Numbers (Including Patterns)
Data Handling
Negative Numbers and Integers
Number Line
HCF and LCM
Playing with Numbers
- Simplification of Brackets
- Finding Factors Using Rectangular Arrangements and Division
- Factors and Common Factors
- Multiples and Common Multiples
- Concept of Even and Odd Number
- Tests for Divisibility of Numbers
- Divisibility by 2
- Divisibility by 4
- Divisibility by 8
- Divisibility by 3
- Divisibility by 6
- Divisibility by 9
- Divisibility by 5
- Divisibility by 11
Sets
Ratio
Proportion (Including Word Problems)
Unitary Method
Fractions
- Concept of Fraction
- Types of Fractions
- Concept of Proper and Improper Fractions
- Concept of Mixed Fractions
- Like and Unlike Fraction
- Concept of Equivalent Fractions
- Conversion between Improper and Mixed fraction
- Conversion between Unlike and Like Fractions
- Simplest Form of a Fractions
- Comparing Fractions
- Addition of Fraction
- Subtraction of Fraction
- Multiplication of Fraction
- Division of Fractions
- Using Operator 'Of' with Multiplication and Division
- BODMAS Rule
- Problems Based on Fraction
Decimal Fractions
Percent (Percentage)
Idea of Speed, Distance and Time
Fundamental Concepts
Fundamental Operations (Related to Algebraic Expressions)
Substitution (Including Use of Brackets as Grouping Symbols)
Framing Algebraic Expressions (Including Evaluation)
Simple (Linear) Equations (Including Word Problems)
Fundamental Concepts
Angles (With Their Types)
Properties of Angles and Lines (Including Parallel Lines)
Triangles (Including Types, Properties and Constructions)
Quadrilateral
Polygons
The Circle
Symmetry (Including Constructions on Symmetry)
Recognition of Solids
Perimeter and Area of Plane Figures
Data Handling (Including Pictograph and Bar Graph)
Mean and Median
- Introduction
- Case 1: To Convert a Common Fraction into a Decimal Fraction
- Case 2: To Convert a Common Fraction into a Decimal Fraction
- Case 3: To Convert a Common Fraction into a Decimal Fraction
- Steps to Convert a Decimal Fraction into a Common Fraction
- Key Points Summary
Introduction
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A common fraction with denominators like 10, 100, or 1000 can easily be written as a decimal fraction.
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Decimal fractions can also be converted into common fractions.
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The process helps simplify calculations and is useful in real-life scenarios, such as measuring and working with money.
Case 1: To Convert a Common Fraction into a Decimal Fraction
When the Numerator has More Digits than Zeros in the Denominator:
Steps:
- Count the digits from the right equal to the number of zeros in the denominator.
- Place the decimal point before those digits.
Example:
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`51250/100` = 512.50
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Here, there are two zeros in the denominator, so place the decimal point after the second digit from the right in the numerator.
Case 2: To Convert a Common Fraction into a Decimal Fraction
When the Numerator has Equal Digits as the Zeros in the Denominator:
Steps:
- Place the decimal point before the number in the numerator and add a zero in the place of the integer.
Example:
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`7/10` = 0.7
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Here, the denominator is 10 (one zero), so place the decimal point after the first digit in the numerator.
Case 3: To Convert a Common Fraction into a Decimal Fraction
When the Numerator has Fewer Digits than Zeros in the Denominator:
Steps:
- Add zeros before the digits to match the number of zeros in the denominator.
- Place a decimal point before them and add a zero before the decimal point.
Example:
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`8/100` = `08/100` = 0.08
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Here, the denominator is 100 (two zeros), so place the decimal point after two digits. To match the number of zeros, add a leading zero in the numerator.
Steps to Convert a Decimal Fraction into a Common Fraction
1. Ignore the decimal point and write the number as it is (this becomes the numerator).
2. Count the digits after the decimal point.
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For 1 digit → write 10 as the denominator.
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For 2 digits → write 100 as the denominator.
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For 3 digits → write 1000 as the denominator, and so on.
Example:
- 19.315 = `19315/1000`
- There are three decimal places, so the denominator is 1000.
Key Points Summary
- Remember: Count zeros in denominator = decimal places to move
- For fractions: Make denominator 10, 100, or 1000 when possible
- For decimals:Number of decimal places = zeros in denominator
- Always simplify fractions to lowest terms
Example Question 1
Find decimal representation of `11/5`.
`11/5 = 22/10 = (20 + 2)/10 = 20/10 + 2/10 = 2 + 2/10 = 2.2`.
Example Question 2
Find the decimal representation of `1/2`.
`1/2 = (1 xx 5)/(2 xx 5) = 5/10 = 0.5`
Therefore, `1/2` is 0.5 in decimal notation.
